Filter routes have the disadvantage that the remote diagnosis of chlorine and hardness or the monitoring of the degree of soiling of mechanical filters, respectively, cannot be carried out or can only be carried out by taking great efforts.
Moreover, it is necessary for reasons of safety, particularly in dialysis water treatments, that a time-consuming manual documentation of the water hardness and/or of the chlorine content should be carried out daily, especially in order to furnish evidence that the toxic chlorine has been removed from the liquid by the filters used.
Existing chlorine sensors for online measurement are often not chlorinated at regular intervals and cannot provide any reliable measurement results in the absence of chlorine in the liquid.
To remove hardly soluble salts, such as calcium and/or magnesium, from the water, softeners are often used. When softeners are used with acidic cation exchange resins, these must be regenerated by means of sodium chloride brine solution at regular intervals.
This regeneration is normally carried out with sodium chloride solution which is provided in a so-called brine container in which salt is dissolved in a predetermined liquid amount. Failure of the regeneration process e.g. because of a missing sodium chlorine brine solution may lead to serious calcification of the downstream systems.
Moreover, softeners tend to show a microbial growth with subsequent contamination of the liquid flowing therethrough because of the relatively large resin volume.
Problems are posed by filter blocking because the resulting exchange of filter material is normally accompanied by operational interruption.